A wellhole or borehole (hereinafter “the borehole”) is generally drilled into the Earth to recover natural deposits of hydrocarbons and/or other desirable materials trapped in a subsurface geological formation (hereinafter “the formation”) in the Earth's crust. The borehole is typically drilled using a drilling system having a drill bit attached to a lower end of a the bottom hole assembly (hereinafter “BHA”). The borehole may be drilled to penetrate a reservoir or other subterranean region of the formation (hereinafter “the formation reservoir”) that contains the trapped hydrocarbons and/or other materials. As a result, the trapped hydrocarbons and/or materials are released and/or recovered from the formation reservoir via the borehole.
The borehole may be also used for treatment applications and a variety of other well related applications. Often, the drilling system is a directional drilling system that enables an operator to change the direction of drilling into the formation to more effectively access the formation reservoir. One example of the direction drilling system is a coiled tubing drilling system having flexibility that is needed to drill deviated wellbores. Additionally, the coiled tubing drilling system may include a variety of systems and devices, such as, steerable motors, articulated subs, push-the-bit systems to facilitate steering for the directional drilling operations.
Directional drilling operations for the drill bit located at the BHA of the drill string are controlled by the operator which makes real-time drilling decisions based on one or more downhole measurements (hereinafter “measurements”). The measurements are detected by the one or more sensors and/or tools associated with the BHA and/or are sent uphole to be accessed and utilized by the operator. Available coiled tubing drilling systems have proven to be limited in certain applications and are often unable to detect the measurements necessary for the operator to facilitate successful and desirable directional drilling operations. As a result, the directional drilling operations may not be steered and/or positioned at the most productive and/or most desirable location within the formation reservoir. For example, available coiled tubing drilling systems are not able to adequately and successfully detect the necessary measurements associated with and/or based on one or more phases in the multiphase borehole fluids. Coiled tubing drilling may be an advantageous drilling technique for underbalanced drilling because coiled tubing drilling does not require connections and the coiled tubing may be slick which may allow formation fluids produced while drilling to flow into the well.